Wetness Kaweco vs Diamine blacks

[Nightjar]

@LizEF and @InesF: I actually wrote to Sailor about the pH of Sailor Black (the basic ink, previously "Jentle"). I was a bit skeptical of the alkalinity reports, thought it might be a sort of internet legend. But they confirm pH is between 10.3 and 11.3, which is indeed seriously alkaline. Kudos to Sailor for very laudable honesty!

[LizEF]

1 hour ago, Nightjar said:

@LizEF and @InesF: I actually wrote to Sailor about the pH of Sailor Black (the basic ink, previously "Jentle"). I was a bit skeptical of the alkalinity reports, thought it might be a sort of internet legend. But they confirm pH is between 10.3 and 11.3, which is indeed seriously alkaline. Kudos to Sailor for very laudable honesty!

 

Wow, that's really helpful information to have!  Thanks for pursuing it.  Also, keep this stuff out of your vintage, pH-sensitve ink sacs!

[Penguincollector]

Here’s a page of common ink pH levels: 

PH of 60 commonly used inks

[Dillo]

To be clear, pH doesn't actually mean a lot when it comes to corrosion and interactions with the pen components. However, pH can give you a clue about how the ink itself is formulated. A lot of the damage that inks can dole out to fountain pens have more to do with the dye formulation and how the dye interacts with the material used to make the pen. Some inks have dyes that can chemically attack the polymers, wedge themselves between the chains and cause staining, or even worse, cleave the chains apart, causing the polymers to break apart.

 

An easy example is acetone. Acetone breaks apart plastics because it has very very small molecules that is attracted to and basically cleave apart the polymer chains. That's why it causes plastics to break apart and is used to remove nail polish or lacquer. This interaction has very little to do with pH, but this is similar to the interactions between ink and the materials used to make pen parts.

 

Another example is vinegar. You can have an ink with the same pH, but does not damage the plastic of the pens, however vinegar has very poor compatibility with the plastics used to make pens.

 

As far as latex sacs go, they tend to fair better with the formulations of some inks that are quite acidic (have a low pH). This doesn't necessarily have anything to with pH but more with the formulation of the ink itself

[LizEF]

50 minutes ago, Dillo said:

To be clear, pH doesn't actually mean a lot when it comes to corrosion and interactions with the pen components. However, pH can give you a clue about how the ink itself is formulated. A lot of the damage that inks can dole out to fountain pens have more to do with the dye formulation and how the dye interacts with the material used to make the pen. Some inks have dyes that can chemically attack the polymers, wedge themselves between the chains and cause staining, or even worse, cleave the chains apart, causing the polymers to break apart.

 

An easy example is acetone. Acetone breaks apart plastics because it has very very small molecules that is attracted to and basically cleave apart the polymer chains. That's why it causes plastics to break apart and is used to remove nail polish or lacquer. This interaction has very little to do with pH, but this is similar to the interactions between ink and the materials used to make pen parts.

 

Another example is vinegar. You can have an ink with the same pH, but does not damage the plastic of the pens, however vinegar has very poor compatibility with the plastics used to make pens.

 

As far as latex sacs go, they tend to fair better with the formulations of some inks that are quite acidic (have a low pH). This doesn't necessarily have anything to with pH but more with the formulation of the ink itself

Well that's interesting!  Clearly there's much too much we don't know, and we're using "hints" to determine safety rather than the trade secrets that actually determine safety...

[Nightjar]

@Dillo I'm sure you're right that there are various components and characteristics of ink that can potentially be harmful to pens, not just high or low pH. But still, pH 11 sounds a bit risky. Perhaps I'll get some Sailor Black and do some little experiments with bits of latex etc.

 

And to be fair to very honest Sailor: a company that is so helpfully transparent is also (I suspect) a company that does careful testing to ensure that its inks are not harmful to modern pens.

[InesF]

10 hours ago, Nightjar said:

Kudos to Sailor for very laudable honesty!

Indeed! It is a rare and valuable information, not easily given and not available from many producers.

I always ask myself what they fear to loose. Colorverse, for example, was the first ink producer I found that published surface tension and pH-value of their inks at their homepage. You may not need to order a sample before knowing if a certain ink will fit your gusher, your desert dry or your well behaving pen.   

 

But, of course, physical and chemical properties are not all and everything when it comes to fountain pen inks ...

... I was told, there is also something like colour ...  😈 

[PJohnP]

Folks,

 

 

We've had discussions, some rather in-depth, on ink pH before now here on FPN.  Here are some starting points on this :

 

https://www.fountainpennetwork.com/forum/topic/202103-ph-level-of-inks-results/

 

If we look around on FPN, we find some occasionally, ahem, intense discussions on methodology, test samples, etc.  Amazing resource materials...

 

 

 

John P.

[Dillo]

@Nightjar I've used Sailor black for a very long time, years and years. I even use it to this day. It has worked well in everything I've used EXCEPT latex sacs. As I was saying in another thread, most Japanese inks use a formulation that is not very good with the latex sacs. The exception to this would be the iron gall type inks that Platinum makes under their classic line and the Platinum Blue Black. Those seem to work fine.

 

Also interesting is that a lot of Japanese pens after the 60's or so started using non-latex sacs. In pens from the big three, I tend to find non-latex sacs in the converters and other parts.

[Nightjar]

@Dillo @PJohnP @InesF 👍🙏